Praseodymium vs Neptunium

PropertyPr PraseodymiumNp Neptunium
Atomic number5993
SymbolPrNp
NamePraseodymiumNeptunium
Categorylanthanideactinide
Standard Atomic Weight140.90766 u237 u
Period67
GroupN/AN/A
Blockss
Phase at STPsolidsolid
Electron configuration[Xe]6s24f3[Rn]7s25f46d1
Oxidation states[0, 1, 2, 3, 4, 5][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.131.36
Electron affinity0.962 eV0.48 eV
Density6770 kg/m³2.025000e+4 kg/m³
Melting point930.85 °C643.85 °C
Boiling point3519.85 °C3901.85 °C
Discovery year18851940